A recent research for the unification of communication technologies has been actively made. An Internet Protocol (IP) Multimedia Subsystem (IMS) is one of the unifications of the communication technologies. IMS is a technology for complexly providing multimedia such as a voice, an audio, a video, large capacity data, etc. through an IP. Based on IMS, services such as a presence service, a Push to talk on Cellular (PoC) service, a Voice over IP (VoIP) service, a video/image sharing service, etc. can be provided.
Among the listed IMS-based services, the presence service is a service designed to provide status information between user Mobile Stations (MSs). Up to now, the presence service is under active development, but it is general that the presence service provides status information input by a user. That is, the user MSs deliver their own presence information to a separate presence server. If there is a request for a presence service from a different MS, the presence server provides presence information of a target MS to the different MS.
As described above, a user can acquire status information on other user MSs through his/her own MS by using the presence service. However, the information acquired through the presence service is limited to information that is input by a called party. Further, the presence service simply provides only status information on a called party, and does not consider providing a seamless service based on the status information on the called party. Thus, here is a need to propose an alternative for acquiring more detailed status information on a called party's MS and more conveniently sharing information using the status information.